An electromagnetic coil assembly is typically made by winding a large number of turns of magnet wire around a bobbin, thereby forming a coil around the bobbin. The bobbin is typically made from non-conductive and non-magnetic material. The coil is connected to an electrical power source via electrical lead wires or terminals. With a voltage across the ends of the magnet wire, an electrical current will circulate through the coil, which in turn will generate a toroidal magnetic flux that envelopes the coil. Soft iron or other ferromagnetic material is normally used to make a yoke that envelops the coil. The yoke provides a magnetic circuit path to concentrate the magnetic flux.
Such electromagnetic coil assemblies have found many applications in components used in the manufacture of vehicles, such as, for examples electromagnetic-actuated clutches. Other, non-vehicular uses also exist, such as in object-lifting electromagnetic devices.
Some electromagnetic coil assemblies can be labour intensive and costly to manufacture. Additionally, some assemblies incorporate many components thus increasing their complexity. There is, therefore, a continuing need for improved electromagnetic coil assemblies.